Judge Christopher Conner in Harrisburg issued the ruling Tuesday in one of more than 30 lawsuits nationwide that have been filed over the law. He says the individual mandate is an unconstitutional extension of authority granted to the federal government under the Constitution's commerce clause.
The suit was filed by a York County couple.
Separate lawsuits have already reached appeals courts in Richmond, Va., Georgia and Cincinnati, with two of those courts ruling in favor of the mandate. The matter is expected to be settled by the U.S. Supreme Court.
Conner was appointed to the federal bench in 2002 by President George W. Bush.